Plunger type electrical switch with arcuate shaped contact means



Feb. 15, 1966 c. A. wooDcocK 3,235,678

PLUNGER TYPE ELECTRICAL SWITCH WITH ARCUATE SHAPED CONTACT MEANS Filed Sept. 20, 1965 /NVE/VTOP United States Patent O 3,235,678 PLUNGER TYPE ELECTRICAL SWITCH WITH ARCUATE SHAPED CONTACT MEANS Charles A. Woodcock, Springfield, Ill., assignor to Stewart-Warner Corporation, Chicago, lll., a corporation of Virginia Filed Sept. 20, 1963, Ser. No. 310,324 6 Claims. (Cl. 200-16) This invention relates to an electric switch, and in particular to a plunger-type electrical switch having a plurality of separate independent switch contacts actuated in unison by a plunger member common to all.

The subject invention embodies a single switch having a selectable number of separate switching units and having a common plunger member including thereon contacts for each of the units. The separate switching units thus can be operative in separate circuits independent of one another responsive to movement of the common plunger member. The units are of substantially identical structure so that they may be stacked and held together by means of simple bolt or rivet construction. Thus, in assembly only the length of the common plunger and the number of units will vary so that the switch may be economically fabricated with a minimum of inventory. The switch is also highly versatile in that both the number of switching units can be readily varied as well as the operative arrangement of each unit.

The basic object of this invention is, therefore, to provide an economically-fabricated, highly-versatile, plungertype switch having substantially identical switch components stacked together to form a single device actuatable by a single plunger.

In the accompanying drawing,

FIG. 1 is a side elevational view of an embodiment of the subject switch;

FIG. 2 is a greatly enlarged sectional view as seen generally from line 2--2 of FIG. 1 of the subject switch; and

FIG. 3 is an exploded perspective view of a single switch unit structure of the subject switch.

As shown in FIGS. 1 and 2, the subject switch 10 includes a plurality of separate electrical switch units indicated generally at 12, 13, 14, and 16 joined together as a single device. A common plunger member 18 having separate contacts 20, 21, 22, 23 and 24 for the units 12 through 16, respectively, extends through all of the switches. The switch 10 includes a threaded mounting stud 26 insertable into an appropriate receiving opening in a frame member 28 and may be secured thereto by means of a nut 30. A spring 32 at the rearward end of the plunger 18 provides a restoring action for the plunger after the actuating force is withdrawn.

Reference is now made to FIG. 3 showing an exploded perspective view of a single switch unit used in the switch. Each unit includes an insulating body composed of identical mating body members 34 and a pair of identical spaced electrical contact members 36 supported by the mated body members.

Each body member 34 is a plastic molded element having on its adjacent mating face 35 a pair of parallel recesses or slots 46 with a central, generally circular recess S0. Each of the parallel recesses is joined to the central recess by an angled recess 48.

The recesses are so formed to receive the electrical contact members 36 which are each formed of strips 37a and b of conductive material such as brass or the like fastened in abutment together in any well known manner. The outer strip 37a is a planar member having an upper extending portion 38a integral and forming a shoulder 41a with a central portion 39a. A narrower lower portion 40a is also formed integral therewith.

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The two portions 39b and 40b of strip 37b are identical and joined to the portions 39a and 40a of the strip 37a to form the Contact member 36. The extending member 38h of each inner strip 37b is angled away from the integral projection 38a of outer strip 37a and is formed at its extended end to deiine an arcuate cylindrical contact 42. The projection 38a of the outer connector strip 37a has a punched tab projection 43 extending inwardly toward the arcuate cylindrical portion 42a of the inner strip 37b to form a locking means therefor within the insulating plastic body 34 as hereinafter described.

Each of the contact members 36 lits within the body members 34 so that the upper extension 38a of the one strip 37a tits within the parallel slot 46. The arcuate circular cylindrical Contact 42a is received within the substantially circular recess 50 of the member 34 while the angular portion of the extension 38h fits within the angled recess 48. The surface extremity 47 of the projection 38b engages the at surface 47b in the body membe 34 and the tab projection 43 engages a shoulder 45 at the end of the parallel slot. These cooperating elements lock the contact members in tight assembly within the assembled switch unit. Each connector 36 is thus held from longitudinal movement with respect to the switch body 34 by the interaction of the inner projection 38h and the tab 43 on the outer strip.

Complementary bosses 51 and recesses 52 on the body members 34 adjacent and surrounding through-openings 56 interlock the bodies 34 to hold the contact members 36 in alignment. The through-openings S6 receive tubular rivets 58 having iianged ends 59 received within counterbores 59a in the outward surfaces of the body members.

The abutting portions 40a and 4Gb of the contact inembers 36 project from the body 34 of the switch unit and form terminal connections for a complementary female electrical connector not shown and not forming a part of this invention.

A through-opening 60 extends through each body member 34 concentric with the substantially circular recess 50 to receive the movable plunger member 18. It may thus be seen that any number of units such as just described may be assembled in a bank with a common plunger actuator 18. The units are aligned so that the openings 62 in each of the rivets 58 may receiveL a fastener rod or rivet 63 of the required length. The rods 63 are inserted through said openings 62 and flared at either end to hold the assembly in secure fashion. Thus, the maximum number of switch units that may be assembled is dictated only by the design requirements and the strength required of the whole assembly.

Each of the switch units, of course, is actuated by the common plunger member which carries contacts 20, 21, 22, 23 and 24 (FIG. 2). The contacts 20 through 24 are electroconductive annuli surrounding a reduced diameter portion 66 of the plunger rod and are maintained at the properly spaced interval by insulating annuli 67, 68, 69, 70 and 71.

The contacts 20 through 24 and spacers 67 through 71 are held in position on the plunger rod so the end contact 24 abuts shoulder 73 on the plunger 18 by means of a semi-spherical retainer 72 press-fit onto the end of the reduced diameter portion 66.

The U-shaped spring 32 retains the plunger member 18 within the assembly and has one leg 74 held in engagement `against the exterior surface of the end switch unit 12 by means of rods 64. The other leg 76 of the U-shaped spring 32 is formed to define a spherical shaped portion 78 in engagement `with the retainer button 72.

The other end of the rods 64 hold a bracket 80 upon which the mounting stud 26 is formed, The stud 26 ii will be remembered is utilized to secure the switch to a frame member 28 with the cooperation of mounting bolt 30.

The switch units 12 through 16 are readily adaptable to operate as normally opened or normally closed switches by merely rearranging the positioning of the contacts 26 through 24 on the plunger member 18. The order of contacts and insulating members may be arranged so that the contacts 2t) through 24 are either initially in contact or out of contact with the arcuate portions 42 of the connectors 36 therewith. For example, in the conguration shown in FIG. 2 switch units 12 and 13 operate as normally closed units and switches 14, 15 and 16 operate as normally open units. This is because contacts 20 and 21 are initially in engagement with their respective contact members 36 whereas contacts 22, 23 and 24 are initially out of engagement with their respective contact members 36.

The subject switch represents a versatile assembly which is fabricated of economically produced members. In a multiswitch arrangement only the plunger and the length of the connecting rods 64 need actually change. An almost infinite variety of switch assemblies are possible if a variety of length plungers and rivets and connecting rods ar inventoried.

While only a single embodiment has been disclosed it will be obvious to those skilled in the art that many other modiiications may be made without departing from the inventive concept of the disclosure. Thus it is desired thatthe invention be limited only by the claims hereinafter following.

What is claimed is: v-1.` An electrical switch comprising a plurality of separate switch units stacked adjacent and aligned with one another, each of said switch units includinga pair of abutting body members having mating recesses and aligned circular through-openings, a pair of separate elec'- troconductive contact members disposed within said recesses and each comprising a pair of strips mated together along a portion thereof, the unmated portion of one of said strips forming a cylindrical arcuate contact disposed concentric with said through-opening, the unmated portion of the other strip forming a lock for said` contact member within said recesses, the mating portions of said strips forming a terminal connection extending exteriorly of said body members, means including a pair of tubular rivets disposed through a respective pair of other aligned openings for securing each of said units in assembly, means including a pair of elongated pins received within respective aligned ones of said tubular rivets of each of said plurality of switch units for holding said units stacked against one another in a common aligned assembly, means including a common plunger extending through the aligned circular through-openings of switch units and axially translatable therein, a like plurality of contact rings replaceably mounted on said plunger, a plurality of insulating sleeve members maintaining said contacts in desired operative positions with respect to said cylindrical arcuate contacts, a button positioned on the end of the plunger operable to define a limit of the plunger in one direction and to contine vthe contacts and insulating sleeves on the plunger, a U-shaped spring having one leg attached to the body of the outermost switch unit by said elongated rods, the other leg of said spring engaging said button to bias said plunger to the limit defined by said button.

2. An electrical switch comprising a plurality of separate switch units stacked adjacent to and aligned with one another, each of said switch units including a pair of abutting .body members having mating recesses and aligned circular through-openings, a pair of separate electroconductive contact members disposed within said recesses and each comprising a pair of strips mated together along a portion thereof, the unmated portion of one of said strips forming a cylindrical @tilllate contact disposed concentric with said through-opening, the unmatcd portion ofthe other strip forming a lock for said Contact member within said recesses, the mating portions of said strips forming a terminal connection extending exteriorly of said body members, means including a pair of tubular rivets disposed through a respective pair of other aligned openings for securing each of said units in assembly, means including a pair of elongated pins received within respective aligned ones of said tubular rivets of cach of said plurality of switch units for holding said units stacked against one another in a common aligned assembly, means including a common plunger extending through the aligned circular through-openings of switch units and axially translatable therein, a like plurality of contact rings replaceably mounted on said plunger, a plurality of insulating sleeve members maintaining said contacts in desired operative positions with respect to said cylindrical arcuate contacts, a button positioned on the end of the plunger operable to define a limit of the plunger in one direction and to conne the contacts and insulating sleeves on the plunger, and means including a spring in engagement with the button for biasing the plunger to the limit defined by said button.

3. In an electrical switch comprising a pluralityv of separate switch units stacked adjacent and aligned with one another, each of said switch units including a pair of abutting body members having mating recesses and aligned circular through-openings, a pair of separate electroconductive contact members disposed within said recesses and each including a cylindrical arcuate contact disposed centrally with said through-opening, a projecting terminal connection extending exteriorly of said body members, means including a pair of tubular rivets disposed through a respective pair of other aligned openings for securing each of said units in assembly, means including a pair of elongated pins received within respective aligned ones of said tubular rivets of each of said plurality of switch units for holding said units stacked against one another in a common aligned assembly, means including a common plunger extending through the aligned circular through-openings of adjacent switches, a like plurality of contact rings replaceably mounted on said plunger, a` plurality of insulating sleeve members positioning sai-d contacts in a desired operative condition with respect to a respective cylindrical arcuate contact switch body, a button positioned on the end of the plunger operable to deiine a limit of the plunger in one direction and to conrm the contacts and insulating sleeve on the plunger, a U-shaped spring having one leg attached to the body member of the outermost switch unit by said elongated rods, the other leg of said spring engaging said button to bias said plunger to the limit dened by said button.

4. An electrical switch comprising plurality of separate switch units stacked adjacent and aligned with one another, each of said switch units including a pair of abutting body members having mating recesses and aligned circular through-openings, a pair of separate electroconductive contact members disposed within said recesses and each including a cylindrical arcuate contact portion disposed concentrically with said through-opening, each of said contact members having a terminal connection extending exteriorly of said body members, means including a pair of tubular rivets disposed through a respective pair of other aligned-openings in Vsaid body members for securing each of said units in assembly, means including a pair of elongated pins received within respective aligned ones of said tubular rivets of each of said plurality of switch units for holding said units stacked against one another in a common aligned assembly, a common plunger extending through the aligned circular through-openings of said switch units and axially translatable therein, a like plurality of contact rings replaceably mounted on said plunger, a plurality of insulating sleeve members positioning said contacts in desired operative positions with respect to said cylindrical arcuate contact portions, a button positioned on the end of the plunger operable to deline a limit of the plunger in one direction and to coniine the contacts and insulating sleeves on the plunger, and means including a spring in engagement with the button for biasing the plunger to the limit defined by said button.

S. In an electrical switch comprising a plurality of separate switch units stacked adjacent and aligned with one another, each of said switch units including a pair of abutting body members having mating recesses and aligned circular through-openings, a pair of separate electroconductive contact members disposed within said recesses and each including a cylindrical arcuate contact disposed centrally with said throughopening, a projecting terminal connection extending exteriorly or said body members, means including a pair of tubular rivets disposed through a respective pair of other aligned openings for securing each of said units in assembly, means including a pair of elongated pins received within respective aligned ones of said tubular rivets of each of said plurality of switch units for holding said units stacked against one another in a common aligned assembly, means including a common plunger extending through the aligned circular through-openings of adjacent switches, a like plurality of contact rings replaceably mounted on said plunger, a plurality of insulating sleeve members positioning said contacts in a desired operative condition with respect to a respective cylindrical arcuate contact switch body, means positioned on the end of the plunger operable to confine the contacts and insulating sleeves on the plunger, and means for biasing the plunger to the limit defined by said button.

6. An electrical switch unit comprising a pair of abutting body members having mating recesses and aligned circular through-openings, a pair of separate electroconductive contact members disposed Within said recesses and each comprising a pair of strips mated together along a portion thereof, the unmated portion of one of said strips for-ming a cylindrical arcuate contact disposed concentric with said through-opening, the unmated portion of the other strip forming a lock for said contact member within said recesses, the mating portions of said strips forming a terminal connection extending exteriorly of said body members, and means including a pair of tubular rivets disposed through a respective pair of other aligned openings in said body members for securing each of said units in assembly.

References Cited by the Examiner UNITED STATES PATENTS 2,554,724 5 /1951 Williams 20G-l1 2,883,492 4/1959 Landers 200-16 X 2,945,098 7/1960 Ludwig 20G-166 X 2,949,511 8/1960 Glueckstein et al ZOO-ll 2,972,033 2/1961 Woodstock 200-159 KATHLEEN H. CLAFFY, Primary Examiner'. BERNARD A. GILHEANY, Examiner. 

6. AN ELECTRICAL SWITCH UNIT COMPRISING A PAIR OF ABUTTING BODY MEMBERS HAVING MATING RECESSES AND ALIGNED CIRCULAR THROUGH-OPENINGS, A PAIR OF SEPARATE ELECTROCONDUCTIVE CONTACT MEMBERS DISPOSED WITHIN SAID RECESSES AND EACH COMPRISING A PAIR OF STRIPS MATED TOGETHER ALONG A PORTION THEREOF, THE UNMATED PORTION OF ONE OF SAID STRIPS FORMING A CYLINDRICAL ARCUATE CONTACT DISPOSED CONCENTRIC WITH SAID THROUGH-OPENING, THE UNMATED PORTION OF THE OTHER STRIP FORMING A LOCK FOR SAID CONTACT MEMBER 